1. Field of the Invention
This invention relates to a high visibility indicator for use with a rotary actuator in order to provide a visual indication, which is viewable from a distance, of the rotary position of the actuator.
2. Description of the Prior Art
Various forms of high visibility indicators are already known, for example as described in European Patent Specification No. 0092714 and U.S. Pat. Nos. 3,238,915; 2,485,942; 3,238,968; and 4,494,556. The present invention is concerned with an alternative form of position indicator that has enhanced visibility, is easy to manufacture, has few component pans and, preferably, when disassembled is easy to reassemble correctly.
Rotary actuators are typically used to drive the spindle of a valve fitted into a pipeline for carrying fluids that may be either gaseous or liquid, in which case the actuator is a 90.degree. actuator. However, such actuators may also be used to actuate a pivotally mounted door or to drive a linearly moving shutter door or to drive component pans of a conveyor system. In some situations the rotary actuator is designed to have a travel significantly greater than 90.degree., for example 120.degree. or 180.degree., and in most situations the actual travel of the actuator can be 4.degree. or 5 .degree. greater than its intended use. Thus, a 90.degree. actuator may be capable of travelling through about 100.degree., the 10.degree. overrun of the actuator being partly available at both ends of the desired 90.degree. travel.